Multi-orbital Hubbard model in infinite dimensions: Quantum Monte Carlo calculation.

Han J. E., Jarrell M., Cox D. L.

Max-Planck Institut fur Festkoerperforschung, Heisenbergstrasse 1, Stuttgart, D-70569, Germany

Using the quantum Monte Carlo technique we compute thermodn. and spectra for the orbitally degenerate Hubbard model in infinite spatial dimensions. With increasing orbital degeneracy we find in the one-particle spectra broader Hubbard bands (consistent with increased kinetic energy), a narrowing Mott gap, and increasing quasiparticle spectral wt. Hund's rule exchange coupling decreases the crit. on-site Coulomb energy for the Mott transition. The metallic regime resistivity for twofold degeneracy is quadratic in temp. at low temps.

Physical Review B, 58 R4199-R4202, 1998.

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